In this paper, we propose a differential eddy current transducer dedicated for detecting and sizing deep surface flaws in thick materials. An analysis of the excitation parameters was carried out in ...order to obtain a good depth resolution of the transducer. Well-chosen parameters of the excitation allow to obtain nearly linear dependence of the output signal amplitude on the flaw depth or high depth resolution of the transducer. The transducer can be calibrated to a particular defect depth and can be utilised in automatic defect classification or gap depth sizing. The results of numerical simulations as well as measurements are presented.
EDDY CURRENT BENCHMARK PROBLEM Chady, T; Sikora, R
Review of Progress in Quantitative Nondestructive Evaluation Volume 27B (AIP Conference Proceedings Volume 975),
01/2008, Letnik:
975
Journal Article
Recenzirano
This paper describes the proposal of a benchmark activity. The objective of the proposed eddy current benchmark problem is to evaluate accuracy of various numerical or semi-analytical methods in ...predicting an eddy current probe multi-frequency response. The probe has a complicated structure and it consists of a cylindrical ferrite core with five symmetrically placed columns. The probe was used to test plates made from nickel-base superalloy INCONEL 600. In the plate a set of defects were introduced. An AC currents consist of 15 harmonic components are applied to the excitation coils. In all cases the specimens were examined by placing the probe on the reverse side of the flaws. The acquired data will be send by email to all participants of the benchmark's activity.
In high-energy heavy-ion collisions, partonic collectivity is evidenced by the constituent quark number scaling of elliptic flow anisotropy for identified hadrons. A breaking of this scaling and ...dominance of baryonic interactions is found for identified hadron collective flow measurements in sNN = 3 GeV Au+Au collisions. In this paper, we report measurements of the first- and second-order azimuthal anisotropic parameters, v1 and v2, of light nuclei (d, t, 3He, 4He) produced in sNN = 3 GeV Au+Au collisions at the STAR experiment. An atomic mass number scaling is found in the measured v1 slopes of light nuclei at mid-rapidity. For the measured v2 magnitude, a strong rapidity dependence is observed. Unlike v2 at higher collision energies, the v2 values at mid-rapidity for all light nuclei are negative and no scaling is observed with the atomic mass number. Calculations by the Jet AA Microscopic Transport Model (JAM), with baryonic mean-field plus nucleon coalescence, are in good agreement with our observations, implying baryonic interactions dominate the collective dynamics in 3 GeV Au+Au collisions at RHIC.
This paper describes the development of a biological control system for
Meloidogyne graminicola using rice root inoculations of the bacterium,
Bacillus megaterium, which was isolated from a ...rice-growing region of Taiwan. Treatment with
B. megaterium resulted in a greater than 40% reduction in nematode penetration and gall formation compared with non-treated rice roots, and, in a separate study, colonization of rice roots with
B. megaterium decreased migration of
M. graminicola to the root zone by nearly 60% compared with that of non-treated roots. Exposure of
M. graminicola eggs to secondary metabolites of
B. megaterium reduced hatching by over 60% compared with eggs not exposed to the bacteria. This paper will present modes of action through which
B. megaterium reduces
M. graminicola damage, and it will discuss challenges in developing nematode biological control systems for rice cultivation in intermittently anoxic and oxic soil environments.
In this letter, measurements of the shared momentum fraction (zg) and the groomed jet radius (Rg), as defined in the SoftDrop algorithm, are reported in p+p collisions at s=200 GeV collected by the ...STAR experiment. These substructure observables are differentially measured for jets of varying resolution parameters from R=0.2−0.6 in the transverse momentum range 15<pT,jet<60 GeV/c. These studies show that, in the pT,jet range accessible at s=200 GeV and with increasing jet resolution parameter and jet transverse momentum, the zg distribution asymptotically converges to the DGLAP splitting kernel for a quark radiating a gluon. The groomed jet radius measurements reflect a momentum-dependent narrowing of the jet structure for jets of a given resolution parameter, i.e., the larger the pT,jet, the narrower the first splitting. For the first time, these fully corrected measurements are compared to Monte Carlo generators with leading order QCD matrix elements and leading log in the parton shower, and to state-of-the-art theoretical calculations at next-to-leading-log accuracy. We observe that PYTHIA 6 with parameters tuned to reproduce RHIC measurements is able to quantitatively describe data, whereas PYTHIA 8 and HERWIG 7, tuned to reproduce LHC data, are unable to provide a simultaneous description of both zg and Rg, resulting in opportunities for fine parameter tuning of these models for p+p collisions at RHIC energies. We also find that the theoretical calculations without non-perturbative corrections are able to qualitatively describe the trend in data for jets of large resolution parameters at high pT,jet, but fail at small jet resolution parameters and low jet transverse momenta.
The local-density approximation is used to find the phonon dispersion relations, total and partial phonon density of states for TiO2 crystal of rutile structure. For that the Hellmann–Feynman forces ...were computed and direct method applied. Some thermodynamic quantities are also presented. Calculated results are analyzed and compared with the experimental neutron scattering and optic data. Good agreement has been achieved. A giant LO/TO splitting is observed for A2u and Eu modes.
Trichoderma harzianum and Trichoderma viride were tested for their capacity to reduce the incidence of the root-knot nematode Meloidogyne incognita on tomato. In vitro studies demonstrated that all ...tested isolates were effective in causing nematode mortality compared with the control. Trichoderma slightly reduced nematode damage to tomato in vivo. Treatment of the soil with the biocontrol agents before transplanting, improved control over treatment directly at transplanting. The Trichoderma isolates could not be re-isolated from the endorhiza, but were successfully re-isolated from the rhizosphere 45 days after fungal inoculation. Only slight increases in plant growth could be measured. The mutualistic endophyte F. oxysporum 162, used as positive control, was more effective in root-knot nematode biocontrol than the Trichoderma isolates.
J/ψ suppression has long been considered a sensitive signature of the formation of the Quark-Gluon Plasma (QGP) in relativistic heavy-ion collisions. In this letter, we present the first measurement ...of inclusive J/ψ production at mid-rapidity through the dimuon decay channel in Au+Au collisions at sNN=200 GeV with the STAR experiment. These measurements became possible after the installation of the Muon Telescope Detector was completed in 2014. The J/ψ yields are measured in a wide transverse momentum (pT) range of 0.15 GeV/c to 12 GeV/c from central to peripheral collisions. They extend the kinematic reach of previous measurements at RHIC with improved precision. In the 0-10% most central collisions, the J/ψ yield is suppressed by a factor of approximately 3 for pT>5 GeV/c relative to that in p+p collisions scaled by the number of binary nucleon-nucleon collisions. The J/ψ nuclear modification factor displays little dependence on pT in all centrality bins. Model calculations can qualitatively describe the data, providing further evidence for the color-screening effect experienced by J/ψ mesons in the QGP.
Dihadron angular correlations in d+Au collisions at sNN=200 GeV are reported as a function of the measured zero-degree calorimeter neutral energy and the forward charged hadron multiplicity in the ...Au-beam direction. A finite correlated yield is observed at large relative pseudorapidity (Δη) on the near side (i.e. relative azimuth Δϕ∼0). This correlated yield as a function of Δη appears to scale with the dominant, primarily jet-related, away-side (Δϕ∼π) yield. The Fourier coefficients of the Δϕ correlation, Vn=〈cosnΔϕ〉, have a strong Δη dependence. In addition, it is found that V1 is approximately inversely proportional to the mid-rapidity event multiplicity, while V2 is independent of it with similar magnitude in the forward (d-going) and backward (Au-going) directions.
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